Electric submersible pump having a plurality of motors operatively coupled thereto and methods of using

ABSTRACT

A downhole electric submersible pump system includes a plurality of motors operatively coupled on a common shaft with an electric submersible pump and a downhole switch mechanism for providing an electrical circuit to each motor of the plurality of motors, wherein the downhole switch mechanism allows power to be delivered to at least one motor. A downhole switch mechanism located in a wellbore, the downhole switch mechanism including an electrical power input for receiving power from an electrical cable and at least two electrical power outputs connected to at least two motors operatively coupled with one or more electric submersible pumps, wherein the downhole switch mechanism is actuated from the surface via the electrical cable and allows power to be delivered to at least one motor of the at least two motors coupled with the one or more electric submersible pumps. A method is also provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority from U.S. Provisional Application No. 61/861,269, filed on Aug. 1, 2013, (Attorney Docket No. T-9438-P/210715-CVN067P), the disclosure of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

One or more embodiments of the present disclosure relate to, for example, electric submersible pumps having a plurality of motors operatively coupled thereto and an electrical switch mechanism allowing selection among one or more of the plurality of motors.

BACKGROUND

Many oil and gas wells must be provided with artificial lift in order to extract hydrocarbons in an effective manner, otherwise the relatively low natural reservoir pressure (particularly in the middle and later years of some wells) is not sufficient to flow the well. Conventionally, the artificial lift may be provided by a variety of methods including injection of CO₂ into the well to force the hydrocarbons up to the surface and by providing downhole pumps to suck in the hydrocarbons and pump them up production tubing to the surface. An electrical submersible pump (or “ESP”) is a form of artificial lift pump designed to draw fluid from a well in the absence of pressure to suit the production rate required. Typically, ESPs in the oilfield have been run as single units on the end of the production tubing (or coiled tubing) within a wellbore. A power cable, attached to the electrical motor unit of the ESP, extends to the surface of the well alongside the production tubing (or coiled tubing) and terminates at the wellhead.

ESP motor failure is a significant contributor to ESP system failure during artificial lift operations. ESP motors typically fail over time due to one or more factors (e.g., high temperatures, short circuits, fluid contamination, etc.). ESP motor and system failure is tremendously expensive, not only due to equipment costs (i.e., motors represent a substantial part of the total cost of the ESP system used in artificial lift operations), but even more so due to production time lost during workovers and other well interventions.

SUMMARY

Embodiments disclosed herein provide electric submersible pumps having a plurality of motors operatively coupled thereto so that one or more backup motors are operated when a first motor fails, thereby postponing or eliminating costly workovers in the event of motor failure downhole.

In one aspect, embodiments disclosed herein relate to a downhole electric submersible pump system including a plurality of motors operatively coupled on a common shaft with an electric submersible pump and a downhole switch mechanism for providing an electrical circuit to each motor of the plurality of motors, wherein the downhole switch mechanism allows power to be delivered to at least one motor of the plurality of motors coupled with the electric submersible pump.

In other aspects, embodiments disclosed herein relate to a method of powering a plurality of motors operatively coupled with an electric submersible pump located downhole in a wellbore, the method including providing a downhole switch mechanism in the wellbore, the downhole switch mechanism being supplied with electrical power, the downhole switch mechanism further being connected to two or more motors operatively coupled on a common shaft with an electric submersible pump, providing electrical power through the downhole switch mechanism to a first motor of the two or more motors, actuating the downhole switch mechanism to break electrical power through the downhole switch mechanism to the first motor and to provide electrical power through the downhole switch mechanism to a second motor of the two or more motors.

In yet other aspects, embodiments disclosed herein relate to a downhole switch mechanism located in a wellbore. The downhole switch mechanism includes an electrical power input for receiving power from an electrical cable and at least two electrical power outputs connected to at least two motors operatively coupled with one or more electric submersible pumps, wherein the downhole switch mechanism is actuated from the surface via the electrical cable and allows power to be delivered to at least one motor of the at least two motors coupled with the one or more electric submersible pumps.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a particular embodiment of an electric submersible pump and a plurality of motors operatively coupled thereto, as well as a downhole switch mechanism, in accordance with one or more embodiments of the present disclosure.

FIG. 2 illustrates an alternative embodiment of an electric submersible pump and a plurality of motors operatively coupled thereto, as well as a downhole switch mechanism, in accordance with one or more embodiments of the present disclosure.

FIG. 3 illustrates, in flowchart form, an embodiment of a method of powering a plurality of motors operatively coupled with an electric submersible pump located downhole in a wellbore in accordance with one or more embodiments of the present disclosure.

DETAILED DESCRIPTION

The aspects, features, and advantages of the present disclosure mentioned above are described in more detail by reference to the drawings, wherein like reference numerals represent like elements. Also, for simplicity, the terminology a first (or upper) motor 106 a is utilized throughout. Similarly, the terminology a second (or lower) motor 106 b I used throughout.

Embodiments of a downhole completion and/or production system for artificial lift operations are disclosed. The downhole system includes a production (or coiled) tubing having an intake into which fluid (e.g., hydrocarbons, water, brine) from the wellbore may be drawn and pumped to the surface. Alternatively, the downhole system may be arranged for injecting fluid into a formation adjacent to the wellbore (e.g., waterflooding, polymer flooding). The downhole system may comprises one or more pumps (e.g., disposed at a lower end of the production tubing). The pumps may comprise electrical submersible pumps having two or more (e.g., hermetically sealed) motors coupled to the pump body.

Two or more motors may be coupled with the pump. The motors may be disposed downhole from the pump or up hole from the pump. Alternatively, one or more motors may be disposed downhole from the pump and one or more motors disposed up hole from the pump. The motors may be located directly adjacent to the pump, or may be indirectly coupled to the pump if other components (e.g., gas separators, sensors, protectors/isolators, thrust bearings, seals) are located therebetween. The motors may range in horsepower (HP) from at least about 100 HP, or 200 HP, or 500 HP, up to about 1000 HP, or 1500 HP, or greater. One skilled in the art will recognize that the horsepower of the motor may be configured based on the wellbore casing size (e.g., use of different sized motors in 5.5 inch casing compared to 7 inch casing). The motors may be installed in tandem having a common longitudinal shaft so that when a first motor is operating the additional motors run idle, generating no significant electrical output. Thus, the common shaft may be a one-piece shaft that may not separate, but in an alternative embodiment of the common shaft, the common shaft may comprise or include separate shafts (e.g., discussed in the context of FIGS. 1-2). The downhole system further comprises an electrical cable that travels from the surface and powers the motors, and a downhole (e.g., electrical) switch mechanism disposed at or near an end of the electrical cable. The downhole electrical switch mechanism may include an electrical input connected to the electrical cable, and two or more electrical outputs connected, by way of motor lead extensions, to the motors to operate each of the motors.

FIG. 1 illustrates a particular embodiment of an electric submersible pump and a plurality of motors operatively coupled thereto, as well as a downhole switch mechanism, in accordance with one or more embodiments of the present disclosure. More particularly, FIG. 1 illustrates a particular embodiment of a downhole completion and production system or string 100 in accordance with one or more embodiments of the present disclosure. A production tubing or string 102 extends along a length of a wellbore from a wellhead (not shown) at the surface. One or more pumps 104 may be disposed along a length of the production tubing 102 having an intake (not shown) into which fluid from the wellbore may be drawn and pumped to the surface. Only one pump 104 is illustrated, however multiple pumps may be included in the production string 102, and each pump may be coupled or associated with one or more motors. The pumps 104 may be any type of electrical submersible pump having two or more (e.g., hermetically sealed) motors 106 coupled to the pump body. For example, the pumps 104 may be multistage centrifugal pumps operating in a vertical position and available from any number of pump manufacturers and/or service companies, as will be understood by one of ordinary skill in the art. For example, the pumps 104 may be ESP pumps available from the General Electric Company.

In certain embodiments, one or more pumps 104 (e.g., at the lower end of the production string 102) may be operated in a manner for performing artificial lift operations in a wellbore. In other embodiments, one or more pumps 104 (e.g., at the lower end of the production string 102) may be operated in a manner for injecting fluids (e.g., water, brine, acids, polymers, surfactants, etc.) into a formation adjacent the wellbore. One of ordinary skill in the art will further understand additional modes in which one or more pumps may be operated or used.

As shown, downhole ESP motors 106 a and 106 b may be coupled with the pump 104 (e.g., at the lower end of the production string 102). While two motors 106 a and 106 b are shown, more than two motors may be coupled with the pump 104. As shown, the motors 106 a and 106 b may be disposed downhole of the pump 104. Alternatively, the motors may be disposed up hole of the pump 104. In yet other embodiments, one or more motors may be disposed up hole of the pump 104, and one or more motors may be disposed downhole of the pump 104. The motors 106 a and 106 b may be located directly adjacent to the pump 104, or the motors 106 a and 106 b may be indirectly coupled to the pump 104 such that other components (e.g., gas separators, sensors, protectors/isolators, thrust bearings, seals) are located therebetween. The motors 106 a and 106 b may be electric motors available from any number of suppliers as will be understood by one of ordinary skill in the art. For example, the motors 106 a and 106 b may be ESP motors available from the General Electric Company, such as (i) the TR-series motors, (ii) E-series motors, (iii) the three-phase two-pole induction motors, and/or (iv) any combination thereof. Motors used in accordance with one or more embodiments disclosed herein may be 100 horsepower (HP) motors up to 1500 HP motors, or greater, as will be understood by one of ordinary skill in the art. It will be understood that the motors having different HP ratings may be used (i.e., motor 106 a can have a different HP rating from motor 106 b), or motors having all the same HP ratings may be used.

In certain embodiments, the motors 106 a and 106 b may be installed in tandem (series) and having a common longitudinal motor shaft 107 so that when a first motor is operating the second motor runs idle. As used herein, idle means that the motor produces an insufficient output to operate pump 104. In embodiments, the motor shaft of the idle motor rotates although no significant electrical output is generated. In certain embodiments, the motors 106 a and 106 b may be located adjacent one another. In other embodiments, the motors 106 a and 106 b may be spaced apart and other components (e.g., gas separators, sensors, protectors/isolators, thrust bearings, seals) located therebetween. Moreover, when the second motor is operating the first motor may run idle.

In other embodiments, a clutch mechanism may be disposed between the motors 106 a and 106 b that provides or transmits power from one motor to another when engaged, but can be disengaged (e.g., the clutch mechanism can disengage the shaft of the lower motor when the upper motor is operating). In yet other embodiments, the motors 106 a and 106 b may have separate motor shafts. For example, FIG. 2 illustrates an alternative embodiment of an electric submersible pump and a plurality of motors operatively coupled thereto, as well as a downhole switch mechanism, in accordance with one or more embodiments of the present disclosure. More particularly, FIG. 2 illustrates an embodiment of a clutch mechanism 202 and an embodiment of the ESP shaft 107 of FIG. 1 comprising separate motor shafts for use with the clutch mechanism 202.

With reference to both FIGS. 1 and 2, a production string 200 is similar to the production string 100, but may include the clutch mechanism 202. The clutch mechanism 202 may be a clutch. Alternatively, the clutch mechanism may include a clutch as well as one or more other components. The clutch mechanism 202 may disengage at least a portion of the common shaft corresponding to the lower motor 106 b and at least a portion of the common shaft corresponding to the upper motor 106 a when the upper motor 106 a is operating. For example, the clutch mechanism 202 may be disposed between the upper motor 106 a and lower motor 106 b, and the clutch mechanism 202 may disengage the shaft of the lower motor 106 b and the shaft of the upper motor 106 a when the upper motor 106 a is operating. In other words, the common shaft (e.g., shaft 107 of FIG. 1) may include separate motor shafts such as (i) an ESP shaft 207 a corresponding to the upper motor 106 a, (ii) an ESP shaft 207 b corresponding to the lower motor 106 b, and so on with an ESP shaft corresponding to each motor. The clutch mechanism 202 may be disposed between the motors 106 a and may disengage or decouple the ESP shaft 207 b corresponding to the lower motor 106 b from the ESP shaft 207 a corresponding to the upper motor 106 a, or vice versa, or decouple in some other manner. By disengaging the ESP shaft 207 b of the lower motor 106 b, the lower motor 106 b and its components may experience less wear and tear, may not run idle, and may even remain unused until the upper motor 106 a experiences a failure.

The clutch mechanism 202 may also provide or transmit power from one motor to another when engaged. Thus, the clutch mechanism 202 may serve as a link between various ESP shafts. For example, the clutch mechanism 202 may be disengaged which may in turn disengage or decouple an ESP shaft from another ESP shaft, or the clutch mechanism 202 may be engaged which may in turn engage or couple an ESP shaft with another ESP shaft.

Turning more specifically to engagement, in a particular embodiment, a downhole electrical switch mechanism 110 (described further hereinbelow) may deliver electrical power through the downhole electrical switch mechanism 110 to the upper motor 106 a while the clutch mechanism 202 and the lower motor 106 b may remain inactive. Also, the lower motor 106 b may not be engaged or coupled to the upper motor 106 a at this point. The lower motor 106 b may be downhole of the upper motor 106 a, and the clutch mechanism 202 may be disposed between the lower motor 106 b and the upper motor 106 a.

In response to a failure of the upper motor 106 a, for example, the downhole electrical switch mechanism 110 may break electrical power through the downhole electrical switch mechanism 110 to the upper motor 106 a and deliver electrical power through the downhole electrical switch mechanism 110 to the lower motor 106 b (e.g., so that the lower motor 106 b begins operating and not the upper motor 106 a). At least a portion of the electrical power to the lower motor 106 b may be provided from the lower motor 106 b to the clutch mechanism 202.

In response to electrical power to the clutch mechanism 202, the clutch mechanism 202 may engage at least a portion of the common shaft corresponding to the lower motor 106 b and at least a portion of the common shaft corresponding to the upper motor 106 a when the lower motor 106 b is operating. For example, in response to receiving electrical power from the lower motor 106 b, the clutch mechanism 202 may engage or couple the ESP shaft 207 b of the lower motor 106 b and the ESP shaft 207 a of the upper motor 106 a, or vice versa, or couple in some other manner. The clutch mechanism 202 may continue to engage or couple the ESP shaft 207 b of the lower motor 106 b and the ESP shaft 207 a of the upper motor 106 a during operation of the lower motor 106 b. Thus, the clutch mechanism 202 may engage (e.g., engage or couple the ESP shaft 207 b and the ESP shaft 207 a) once the lower motor 106 b is activated, in other words, the clutch mechanism 202 may engage in response to activation of the lower motor 106 b. Indeed, the downhole electrical switch mechanism 110 may allow power to be delivered to the lower motor 106 b, and the clutch mechanism 202 may receive power from the lower motor 106 b. The clutch engagement may depend on whether the clutch mechanism 202 is either electro-magnetic or mechanical or hydraulic. Thus, the clutch mechanism 202 may be at least one of electro-magnetic, mechanical, or hydraulic.

As an example, if the clutch mechanism 202 is electro-magnetic, electrical power may be utilized for its operation. This power could be supplied once the lower motor 106 b is energized. The clutch mechanism 202 may then utilize electrical communication with the lower motor 106 b's power so that part of the electrical power can be utilized for the clutch mechanism 202's operation.

As another example, if the clutch mechanism 202 is mechanical (e.g., friction disk) or hydraulic, an electronic signal may be used for its engagement. This signal can be modulated over the lower motor 106 b's supplied cable. An electronic circuit, external or integrated to the lower motor 106 b, may receive this signal and may activate the clutch mechanism 202. The clutch mechanism 202 may utilize electrical communication with the lower motor 106 b. An alternative may be to transmit the signal through a cable that connects the downhole electrical switch mechanism 110 and the clutch mechanism 202. This could be a downhole instrumentation cable or a fiber optic cable. The fiber optic cable may occupy less space in the annular space.

As another example, if the clutch mechanism 202 is hydraulic, the engagement may also be made using the internal motor oil. For instance, a small pump or turbine may be installed between the clutch mechanism 202 and the lower motor 106 b. This pump or turbine may be coupled to the lower motor 106 b. Once the lower motor 106 b is activated, the pump or turbine may boost motor oil toward the clutch mechanism 202's internals, which may cause the clutch engagement. An alternative may be to use motor oil thermal expansion for engaging the clutch mechanism 202. Once the lower motor 106 b is activated, the internal temperature of this motor may increase (as well as the upper motor 106 a may decrease). The increment of temperature may cause the thermal expansion of the motor oil increasing the internal pressure of the oil inside the lower motor 106 b. The increase of internal pressure may be used for creating an up-thrust force against the clutch mechanism 202 causing its engagement.

Those of ordinary skill in the art will appreciate that the examples in this disclosure are not exhaustive. Moreover, terminology such as “at least a portion of the common shaft corresponding to the lower motor” may include, for example, an end of the separate motor shaft illustrated as ESP shaft 207 b corresponding to the lower motor 106 b, the entire separate motor shaft illustrated as ESP shaft 207 b corresponding to the lower motor 106 b, etc. Similarly, terminology such as “at least a portion of the common shaft corresponding to the upper motor” may include, for example, an end of the separate motor shaft illustrated as ESP shaft 207 a corresponding to the upper motor 106 a, the entire separate motor shaft illustrated as ESP shaft 207 a corresponding to the upper motor 106 a, etc.

Terminology such as “when the lower motor is operating” may include, for example, the lower motor 106 b begins operating, during operation of the lower motor 106 b, etc. Similarly, terminology such as “when the upper motor is operating” may include, for example, the upper motor 106 a begins operating, during operation of the upper motor 106 a, etc.

Furthermore, the order of disengaging at least a portion of the common shaft corresponding to the lower motor and at least a portion of the common shaft corresponding to the upper motor may depend on the specific implementation, and may include, for example: (i) the at least a portion of the common shaft corresponding to the lower motor may be disengaged from the at least a portion of the common shaft corresponding to the upper motor, (ii) the at least a portion of the common shaft corresponding to the upper motor may be disengaged from the at least a portion of the common shaft corresponding to the lower motor, etc. Similarly, the order of engaging at least a portion of the common shaft corresponding to the lower motor and at least a portion of the common shaft corresponding to the upper motor may depend on the specific implementation, and may include, for example: (i) the at least a portion of the common shaft corresponding to the lower motor may be engaged to the at least a portion of the common shaft corresponding to the upper motor, (ii) the at least a portion of the common shaft corresponding to the upper motor may be engaged to the at least a portion of the common shaft corresponding to the lower motor, etc.

With reference to FIGS. 1 and 2, an electrical cable 108 that travels from the surface (which may be several hundred or thousand feet) powers the motors 106 a and 106 b through a downhole electrical switch mechanism 110. In embodiments, the electrical cable 108 may be secured to the production string 102 by way of practically any attachment mechanism used in the context of ESP's (illustrated as an attachment mechanism 204), standard clamps or cable protectors (not shown) as will be understood by one of ordinary skill in the art. For example, clamps or cable protectors may be disposed at about every 30 feet or each joint of the production tubing 102. In embodiments, the electrical cable 108 is encapsulated within a coiled tubing umbilical. The submersible electrical cable 108 may be used for submersible electrical pumps in a deep well and is capable of withstanding harsh conditions used in both fresh and salt water. Further, the submersible electrical cable 108 may be a single or multiple conductor type, and may be flat or round in cross section. In certain instances, the submersible electrical cable 108 is color-coded for identification and may include an overall cable jacket that is also color-coded.

In embodiments, the electrical cable 108 may be a three-phase (3-phase) or four-phase (4-phase) cable, in which plain copper and/or tinned copper are used as a conductor. For example, the electrical cable 108 may comprise a PVC 3-phase or 4-phase cable, either flat or round. Alternatively, the electrical cable 108 may comprise a rubber 3-phase or 4-phase cable, either flat or round. Still further, the electrical cable 108 may comprise a flat drincable, or HO7RN-F cable, which will be understood by one of ordinary skill in the art. For example, the electrical cable 108 may be an ESP cable available from the General Electric Company or available from any number of suppliers as will be understood by one of ordinary skill in the art. The electrical cable 108 may be General Electric Company's Powerline™ cable.

The downhole electrical switch mechanism 110 may be disposed at or near an end of the electrical cable 108. The downhole electrical switch mechanism 110 may be a downhole electrical switch. The downhole electrical switch mechanism 110 may include a downhole electrical switch as well as other components. Of note, although a downhole switch mechanism may be the downhole electrical switch mechanism 110, such need not be the case in some embodiments. For example, the downhole switch mechanism may be a downhole electrical switch or simply a downhole switch.

Nonetheless, the downhole electrical switch mechanism 110 may be separate from, or it may be integral with or incorporated into the ESP housing. The downhole electrical switch mechanism 110 may be any type of electrical component that can switch an electrical circuit, interrupting or diverting it from one conductor to another. For example, the downhole electrical switch mechanism 110 may include an electrical power input 212 connected to the electrical cable 108 and at least two electrical power outputs 214 a and 214 b connected to motor lead extensions 112 a and 112 b. The downhole electrical switch mechanism 110 includes internal conductive pieces or contacts (not shown), which may be metal, that touch to complete (make) a circuit or separate to open (break) the circuit between the electrical cable 108 and the motor lead extensions 112 a and 112 b to operate either of the motors 106 a and 106 b, respectively. For example, the motor lead extensions 112 a and 112 b may be lead extensions available from the General Electric Company or available from any number of suppliers as will be understood by one of ordinary skill in the art. While two motor lead extensions 112 a and 112 b are shown, there may be more than two motor lead extensions depending upon the number of motors. The downhole electrical switch mechanism 110 may utilize an electrical signal to make and break the circuit to the motors 106 a and 106 b, through respective motor lead extensions 112 a and 112 b, to operate motors 106 a and 106 b, respectively. Each motor 106 a and 106 b has a motor lead extension 112 a and 112 b, respectively, that extends from each respective motor to the downhole electrical switch mechanism 110 (which may extend up to 100 feet or more).

FIG. 3 illustrates, in flowchart form, an embodiment of a method of powering a plurality of motors operatively coupled with an electric submersible pump located downhole in a wellbore in accordance with one or more embodiments of the present disclosure. With reference to FIGS. 1, 2, and 3, a method 300 of powering a plurality of motors may be utilized for operating the electrical submersible pump 104 (e.g., at the lower end of the production string 102).

Turning to the method 300, the method 300 may include, at 302, providing a downhole switch mechanism in the wellbore, the downhole switch mechanism being supplied with electrical power, the downhole switch mechanism further being connected to two or more motors operatively coupled on a common shaft with an electric submersible pump. For example, a downhole electrical switch mechanism 110 may be provided, the downhole electrical switch mechanism 110 being supplied electrical power through an electrical cable 108 running from the surface, or alternatively through a separate electrical cable. The downhole electrical switch mechanism 110 is connected by way of motor lead extensions 112 a and 112 b to motors 106 a and 106 b, respectively, coupled to the pump 104 (e.g., at the lower end of the production string 102) by the ESP shaft 107 (FIG. 1) or the ESP shafts 207 a and 207 b (FIG. 2).

The method 300 may include, at 304, providing electrical power through the downhole switch mechanism to a first motor of the two or more motors. The method 300 may also include, at 306, disengaging at least a portion of the common shaft corresponding to the second motor and at least a portion of the common shaft corresponding to the first motor when the first motor is operating. For example, in embodiments, when the production string 102 is run, the downhole electrical switch mechanism 110 is set in a first position to make a circuit between the electrical cable 108 and the first or upper motor 106 a, thereby powering the first motor 106 a. The circuit between the electrical cable 108 and the second (or lower) motor 106 b is broken at this time, and thus the second motor 106 b receives no power at this time and runs idle. An alternative to the second motor 106 b running idle was discussed hereinabove in connection with FIG. 2, namely, the clutch mechanism 202 may be utilized to disengage at least a portion of the common shaft corresponding to the second (or lower) motor 106 b, such as disengage the ESP shaft 207 b from ESP shaft 207 a, when the first (or upper) motor 106 a is operating.

The method 300 may include, at 308, actuating the downhole switch mechanism to break electrical power through the downhole switch mechanism to the first motor and to provide electrical power through the downhole switch mechanism to a second motor of the two or more motors. For example, subsequently, the downhole electrical switch mechanism 110 may be moved to a second position to make a circuit between the electrical cable 108 and the second motor 106 b, thereby powering the second motor 106 b. The circuit between the electrical cable 108 and the first motor 106 a is broken at this time, and thus the first motor 106 a receives no power at this time and runs idle. At any particular instant, the downhole electrical switch mechanism 110 may be activated to break the circuit with the first motor 106 a and make the circuit with the second motor 106 b, thereby delivering power to the second motor 106 b while the first motor 106 a runs idle. For example, if the upper motor 106 a fails due to any reason, the downhole electrical switch mechanism 110 allows selection of the lower motor 106 b to continue operating the pump. In embodiments, the downhole electrical switch mechanism 110 may switch between motors 106 a and 106 b based on downhole reservoir or motor conditions (e.g., information such as motor winding temperature, motor load, power supply, downhole sensor data). Alternatively, in certain embodiments, the second motor 106 b may be operated before the first motor 106 a. Still further, more than the two motors 106 a and 106 b shown may be included with a single electric submersible pump 104, such that the downhole electrical switch mechanism 110 is configured to make and break circuits with each individual motor coupled with the electric submersible pump 104. In certain embodiments, only one motor at a time may operate the electric submersible pump 104 while any other motors coupled therewith to the electric submersible pump 104 remain idle. Alternatively, more than one motor at a time may operate the electric submersible pump 104 to provide extra power and pumping and/or injecting capabilities. One of ordinary skill in the art will understand that one or more motors at a time can be operated while any additional motors can remain idle.

Furthermore, if the clutch mechanism 202 was utilized at 306 to disengage the ESP shaft 207 b of the second (or lower) motor 106 b, the disengagement of the ESP shaft 207 b may be reversed at 308. For example, the method 300, at 309, may include engaging at least a portion of the common shaft corresponding to the second motor and at least a portion of the common shaft corresponding to the first motor when the second motor is operating. For example, as described hereinabove in connection with FIG. 2, the clutch mechanism 202 may be utilized to engage at least a portion of the common shaft corresponding to the second (or lower) motor 106 b, such as engage the ESP shaft 207 b with the ESP shaft 207 a, when the second (or lower) motor 106 b is operating.

The method 300 may include, at 310, performing artificial lift operations in the wellbore. The method 300 may also include, at 312, injecting fluids into a formation adjacent the wellbore. For example, the electric submersible pump or pumps 104 may be utilized to perform artificial lift operations and/or to inject fluids depending on the particular implementation and/or needs of the users.

The claimed subject matter is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of one or more embodiments disclosed herein in addition to those described herein will become apparent to those skilled in the art from the foregoing descriptions. Such modifications are intended to fall within the scope of the appended claims. For example, although one pump is illustrated in FIGS. 1 and 2, those of ordinary skill in the art will appreciate that more than one pump may be utilized. For example, a single downhole electrical switch mechanism 110 may provide power to separate motors corresponding to separate pump completions. Moreover, the use of multiple separate cables may be avoided, and instead, the single cable 108 coupled to the single downhole electrical switch mechanism 110 may be utilized to power motors in various pump completions.

Furthermore, for example, sensors may be included on the surface or downhole in additional embodiments. Furthermore, the surface may include entities configured to receive data from downhole, process data, compare data, send data downhole, etc. The entities may include computing apparatuses, wherein a particular computing apparatus includes at least one processor and/or at least one memory bearing program code (e.g., data and instructions) that when executed by the processor cause the computing apparatus to perform actions, methods, etc. User input may or may not be needed depending on the task.

As used in this specification and the following claims, the terms “comprise” (as well as forms, derivatives, or variations thereof, such as “comprising” and “comprises”) and “include” (as well as forms, derivatives, or variations thereof, such as “including” and “includes”) are inclusive (i.e., open-ended) and do not exclude additional elements or steps. Accordingly, these terms are intended to not only cover the recited element(s) or step(s), but may also include other elements or steps not expressly recited. Furthermore, as used herein, the use of the terms “a” or “an” when used in conjunction with an element may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” Therefore, an element preceded by “a” or “an” does not, without more constraints, preclude the existence of additional identical elements. Furthermore, the use of the terminology “lower end of the production string” and the like is meant to provide an example and should not limit the scope of the claims.

The use of the term “about” applies to all numeric values, whether or not explicitly indicated. This term generally refers to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term can be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% can be construed to be a range from 0.9% to 1.1%. 

What is claimed:
 1. A downhole electric submersible pump system comprising: a plurality of motors operatively coupled on a common shaft with an electric submersible pump; and a downhole switch mechanism for providing an electrical circuit to each motor of the plurality of motors; wherein the downhole switch mechanism allows power to be delivered to at least one motor of the plurality of motors coupled with the electric submersible pump.
 2. The electric submersible pump system of claim 1, wherein the downhole switch mechanism is electrically actuated.
 3. The electric submersible pump system of claim 1, further comprising an electrical cable providing electrical power to the downhole switch mechanism.
 4. The electric submersible pump system of claim 1, wherein the downhole switch mechanism comprises an electrical power input connected to an electrical cable, and a plurality of electrical outputs.
 5. The electric submersible pump system of claim 4, further comprising respective motor lead extensions extending from the plurality of electrical outputs to each motor of the plurality of motors.
 6. The electric submersible pump system of claim 1, wherein the plurality of motors includes an upper motor and a lower motor, wherein the lower motor is downhole of the upper motor, further comprising a clutch mechanism disposed between the lower motor and the upper motor.
 7. The electric submersible pump system of claim 6, wherein the clutch mechanism is configured to disengage at least a portion of the common shaft corresponding to the lower motor and at least a portion of the common shaft corresponding to the upper motor when the upper motor is operating.
 8. The electric submersible pump system of claim 6, wherein the clutch mechanism is configured to engage at least a portion of the common shaft corresponding to the lower motor and at least a portion of the common shaft corresponding to the upper motor when the lower motor is operating.
 9. The electric submersible pump system of claim 6, wherein the clutch mechanism is electro-magnetic, mechanical, or hydraulic.
 10. The electric submersible pump system of claim 6, wherein the downhole switch mechanism allows power to be delivered to the lower motor, and wherein the clutch mechanism receives power from the lower motor.
 11. The electric submersible pump system of claim 1, wherein the plurality of motors are disposed downhole from the electric submersible pump.
 12. The electric submersible pump system of claim 1, wherein the plurality of motors are disposed up hole from the electric submersible pump.
 13. The electric submersible pump system of claim 1, wherein the plurality of motors are disposed up hole and downhole from the electric submersible pump.
 14. The electric submersible pump system of claim 1, wherein one motor of the plurality of motors is electrically powered while remaining motors are idle.
 15. A method of powering a plurality of motors operatively coupled with an electric submersible pump located downhole in a wellbore, the method comprising: providing a downhole switch mechanism in the wellbore, the downhole switch mechanism being supplied with electrical power, the downhole switch mechanism further being connected to two or more motors operatively coupled on a common shaft with the electric submersible pump; providing electrical power through the downhole switch mechanism to a first motor of the two or more motors; and actuating the downhole switch mechanism to break electrical power through the downhole switch mechanism to the first motor and to provide electrical power through the downhole switch mechanism to a second motor of the two or more motors.
 16. The method of claim 15, further comprising electrically actuating the downhole switch mechanism.
 17. The method of claim 15, wherein the second motor is downhole of the first motor, further comprising disengaging at least a portion of the common shaft corresponding to the second motor and at least a portion of the common shaft corresponding to the first motor when the first motor is operating.
 18. The method of claim 15, wherein the second motor is downhole of the first motor, further comprising engaging at least a portion of the common shaft corresponding to the second motor and at least a portion of the common shaft corresponding to the first motor when the second motor is operating.
 19. A downhole switch mechanism located in a wellbore, the downhole switch mechanism comprising: an electrical power input for receiving power from an electrical cable; and at least two electrical power outputs connected to at least two motors operatively coupled with one or more electric submersible pumps; wherein the downhole switch mechanism is actuated from the surface via the electrical cable and allows power to be delivered to at least one motor of the at least two motors coupled with the one or more electric submersible pumps.
 20. The downhole switch mechanism of claim 19, wherein the downhole switch mechanism breaks electrical power through the downhole switch mechanism to a first motor and delivers electrical power through the downhole switch mechanism to a second motor. 